David Cameron has spoken to the German Chancellor Angela Merkel and the French President Francois Hollande about the crisis in Ukraine, Number 10 has revealed.
Ahead of the meeting of EU leaders on Thursday, Downing Street said they all agreed "the international community should speak with one voice and send a clear message to Russia that its actions in Ukraine were completely unacceptable."
They also talked about the importance of "the costs and consequences for the Russian government of continuing to violate Ukraine’s sovereignty."
Pro-Russia activists recaptured administrative headquarters in the Ukrainian city of Donetsk and flew the Russian flag from its roof.
ITV News' Europe Correspondent describes the tense atmosphere surrounds a central government building in Donetsk .
New footage obtained by ITV News shows Russian troops firing warning shots as Ukrainian soldiers approached during a tense stand-off today.